I recently thought about getting a new powerhead for my tank. I have a 300L tank (120 cm long, 50 cm tall and 50 cm wide) with one angelfish, two clownloaches (I know, they need to be in groups of six), 4 cory catfish and one bristlenose catfish. I also have a ton of plants and one large piece of wood.

I thought about getting a 6000L/H one because it has additional diractional flow attachements, but I am afraid that it will be too big.

I need the directional flow attachements so I could point one on my sand, and it will blow the fish waste away. The other one would be pointed at the surface.

My question is: Is the 6000L/H one too big? If yes, what size would you recommend?

ok...here in the US we go by GPH and not LPH....but that's ok i can roughly figure it out....lol
6000 LPH is a huge amount of current..1500 GPH...dropping down to a 3000 LPH/750 GPH will be considerably better...especially if you are going to split it up..